Combination amplifier and oscillator unit



Feb. 23, 1960 R. G. FERRls 2,925,776

COMBINATION AMPLIFIER AND oscILLA'roR UNIT Filed May 15, 1944 lNVENTOR A NEY United States Patent O COMBINATION AMPLIFIER AND OSCILLATOR UNIT Robert G. Ferris, Harvard, Ill., assigner to the United States of America as represented by the Secretary of the Navy Application May 15, 1944, Serial No. 535,697

16 Claims. (Cl. 102--70.2)

The invention relates generally to radio-controlled proximity fuzes for shells and other projectiles, and is more particularly directed to improvements in fuzes of the type disclosed in the copending application of M. A. 'Iuve et al., Serial No. 471,388, filed January 6, 1943, for Fuze.

An important object of the present invention is to improve the arrangement of the parts of such fuzes, particularly the mounting, disposition and interconnection of the amplifier and oscillator sections thereof, and of various components of such sections.

R-adio proximity fuzes of the indicated variety make use of an oscillator for generating electromagnetic waves at radio frequencies, and embody an amplifier connected to the oscillator and serving to amplify the pulses created in the oscillator upon the approach of the projectile to a target, a thyratron being also incorporated, operative by the output of the lamplifier to fire a detonator. It has been the practice to connect the oscillator unit to the amplifier by means of plug and socket connectors, the oscillator unit largely filling the nose of the projectile and the amplifier and thyratron unit beingl mounted in the body of the projectile. This arrangement occupies a large amo-un-t of space in the shell so that the space for the eX- plosive charge is somewhat limited. Also, it has been found that the plug and socket connectors sometimes do not establish proper contact, with the result that the pulses from the oscillator unit are not fed to the amplifier properly.

Another object of the invention is, therefore, to provide a combination amplifier and oscillator unit which is so designed and constructed that all of the components of both the amplifier and oscillator units will be compactly contained within the nose of the projectile.

A further object of the invention is to provide a Aunit of this character which is relatively simple in construction and wherein the electrical connections between the amplifier and oscillator units are so permanent and reliable as to insure proper connections between said units at all times.

Other objects of the Iinvention will appear hereinafter.

The single figure constituting the drawing is a longitudinal sectional view of a fuze incorporating the principles of the present invention, fragmentarily showing the forward end of a projectile to which the fuze is attached, and sho-wing the improved combination amplifier and oscillator unit as it appears properly mounted in the forward end of a projectile.

A fuze made in accordance with the invention comprises a nose, preferably of plastic material, which is fitted in the forward end of the projectile and clamped in place by a suitable ring. The plastic nose is formed with an axial bore provided with a reduced portion at its forward end communicating with the apex of the nose through an axial opening. An antenna is fitted about the apex or forward portion of the nose and is held in place by a screw which is held tightly in a threaded socket "ice in the apex. The oscillator unit is fitted in the bore and is electrically connected with the antenna by a threaded stem. The amplifier is, in turn, fitted in the bore inwardly of the oscillator unit and is sealed in place in a suitable manner. Plug and socket connections are made from the amplifier to a battery mounted in the inner can of the projectile.

Referring more particularly to the drawing, the numeral 1 indicates generally the forward end of a projectile which is only fragmentarily shown and which maybe of conventional or any other suitable construction. A can 4 is screwed in-to an internally threaded opening 3 at the forward end of the projectile casing, and is provided with an externally threaded forwardly projecting portion 5. As will be seen, the forward end portion of the can 4 is provided with a tapered inner wall 6.

Fitted in the can 4 is a nose unit 7 formed of plastic or other suitable insulating material. The nose is provided with an annular seat 8 shaped to confront the wall 6. Below the seat, the nose is provided with a reduced cylindrical portion 9 which fits tightly in the neck of the can 4. Above the seat 8, the nose unit is slightly flared to define a shoulder 10 which overlies the rim of the can portion 5 and assists in limiting the nose against downward movement in the can 4. The nose unit, above the shoulder 10, is provided with a frusto-conical restricted portion 1-1 which terminates at its forward end in a cylindrical portion 12, said portions 11 and 12 definingV a seat for a locking ring 13 which is (fitted about the nose unit and screwed on the portion 5. The locking ring effectively locks thenose unit in place on the can 4.

Forwardly of the cylindrical portion 12, the nose is of a conventional truncated conic shape, terminating at its apex in a shoulder 14 surrounding a counterbored and tapped opening 1S.

Formed axially in the nose unit 7 and extending from the base throughout the greater pontion of its length is a recess 15 communicating with a smaller recess or chamberv 16 which, in turn, communicates with a socket 17. An axial bore 19 connects socket 17 and the counterbored opening 18. An annular series of connector pins 21 is carried by the base of the nose unit 7, mounted in sockets 20 and disposed concentrically about the recess 15.

Mounted in the recess 15 and projecting into the chamber 16 is an oscillator unit generally designated 22. The oscillator unit is similar electrically to that disclosed in the aforementioned copending application. Instead of using an enclosing can, however, as in the Tuve et al. construction referred to, l eliminate such container entirely, the oscillator unit being supported by a tube or sleeve of insulating material 23 which extends inside some of the components of the oscillator, and outside others. The tank coil 24 is wound upon the forward end portion of the tube, while ocsillator vacuum tube 25 whichl is connected electrically in circuit with the tank coil 24 (and with the other components of [the oscillator unit) .is housed within the tube'23. Other components of the oscillator, such as the resistors 26, 27 may be con'' centrically arranged around the tube within the recess 15.

A nosepiece 29 is threaded into the tapped opening 18 and may assist in retaining the frusto-conic antenna ele` ment 30, which is formed of copper or other suitable conducting material. The nosepiece also provides electrical connection with the antenna element and is axially bored and tapped to receive a screw 28. Screw 28 extends rearwardly to contact the variable condenser 28a, providing electrical connection between the nosepiece and the condenser. This condenser 28a isshown'only diagrammatically, and in actual practice may be yany conventional type of small-capacitance variablegcondenser, such as those known as trimmers, for instance. Obviously, the screw 28 may adjust a condenser of this type by varying the separation of the plates as by bearing against the movable one in the customary Way, and may equally well shiftthe movable element of any other type of variable condenser by either translation or rotation, or both simultaneously. Simply shown, the condenser 28a may comprise a movable plate 36 connected to the antenna through the screw 28 and a stationary plate 37 electrically connected to the tank coil. Electrical connection is also made between the screw 28 and the tank coil. Since one end of the tank coil and one side of the condenser are connected together and to the antenna, such connection will be seen to be very easy to effectuate, and since no special insulation of these parts or of the screw is required, a very simple and rugged construction is provided which it is virtually impossible to shortcircuit or injure even by very rough handling. The screw 28 also performs the mechanical function of tuning the variable condenser, to permit changing the loading of the oscillator. The condenser is mounted at one end of the supporting tube 23, and the entire assemblage may, if desired, be additionally secured in position by filling the remaining voids in recess 15 with potting compound or other suitable material.

Mounted in the recess 15 beneath the oscillator unit 22 is an amplier unit 31. The amplifier unit is similar electrically to the amplifier unit disclosed in the previously mentioned copending application. It is relatively small in size and surrounded by a copper shield 32. Suitable conductors are permanently connected between the output of the oscillator unit and the input of the amplifier unit, and connections are made to a battery unit 33 through the pins 21 which engage in sockets 34 on the battery unit.

Confined between the forward end of the battery unit 33 and the rear end of the nose unit 7 is a retaining disc or cover 35 which is secured to said nose unit and serves to prevent displacement of the amplilier and oscillator unit from the recesses 15 and 16. It should be understood that suitable gaskets are employed to prevent entry of liquids into the projectile.

The operation of the new fuze is similar in every respect to that of the radio proximity fuze described in the copending application previously referred to. However, the compactness of the structure described in this specification permits enclosure of both the amplifier and oscillator units within the nose of the projectile. As a result, only a small amount of space is utilized and positive connection between the amplifier and oscillator units is assured at all times by the permanent interconnection of the oscillator and amplifier.

While I have specifically described a preferred form of my invention, it is to be understood that its actual scope is defined solely by the appended claims.

I claim:

1. A radio-controlled fuze construction including an insulating housing adapted to form a part of the nose of a projectile and of generally ogival shape, said housing having an axial chamber therein, an antenna element carried by said housing, an oscillator unit arranged within said chamber, .said oscillator unit including an electron tube, a coil and a variable condenser, said three last mentioned elements being electrically connected to one another and to said antenna element, and means for tuning the variable condenser from outside the housing, including an adjusting screw, accessible from outside the housing, and providing mechanical connection to said condenser and also providing electrical connection between said condenser and the antenna element.

2. A radio-controlled fuze construction including an insulating housing adapted to form a part of the nose of a projectile and of generally tapering shape, said housing having an axial chamber therein, an oscillator unit ar ranged within said chamber, said oscillator unit including an electron tube, a coil and a variable condenser, said three last mentioned elements being electrically connected to one another, said electron tube being mounted axially within said chamber, a tubular insulating support carrying said coil and mounted concentrically with respect to said electron tube, a variable condenser also substantially axially disposed and arranged at one end of said support, and means for tuning said variable condenser including an elongated mechanical adjusting element extending inwardly from the smaller end of said housing to mechanical connection with said condenser.

3. A fuze construction as set forth in claim 1 in which one end of said chamber is open at the larger end of said housing, and in which said oscillator unit occupies only a portion of the length of said chamber, and an amplifier unit arranged between the oscillator unit and the open end of said chamber.

4. A radio-controlled fuze construction including an insulating housing adapted to form a part of the nose of a projectile and of generally tapering shape, said housing having an axial chamber therein open at the larger end of the housing, an antenna element carried by and near the smaller end of said housing, an oscillator unit arranged Within said chamber and including an electron tube, a coil and a variable condenser, all of said three last mentioned elements being arranged coaxially with respect to the housing, a tubular internal support within said chamber surrounding said electron tube and carrying said coil, an adjusting screw extending inwardly from the smaller end of said housing to make mechanical and electrical connection with said variable condenser whereby the latter may be tuned from outside the housing, said adjusting screw also being electrically connected to said antenna element, an amplifier unit including a conrainer arranged between said oscillator unit and the open end of said chamber and serving to retain the oscillator unit, and means for retaining said container in thel chamber, said internal support serving as a spacer for said container.

5. A projectile nose unit of the character described having a recess therein, means for mounting the nose unit in the forward end of the projectile, an antenna carried on the nose unit, an oscillator unit carried within the recess, said oscillator unit including an electron tube, a coil, and a condenser, electrically interconnected so as to produce radio frequency oscillations, a tubular support surrounding said electron tube and carrying said coil, an amplifier unit carried Within the recess and electrically connected with the oscillator unit, and means electrically connecting the oscillator unit with the antenna for emitting radio frequency waves therefrom.

6. In a projectile, a unit of the character described including a nose unit', means mounting the nose unit in the projectile, an oscillator unit mounted in the nose unit, said oscillator unit including an electron tube, a coil, and a condenser all electrically interconnected so as to pro duce radio frequency oscillations, a tubular support surrounding said electron tube and carrying said coil, and an amplifier unit mounted in the nose unit and electrically connected with the oscillator unit.

7. A radio-controlled fuze including an insulating housing designed to form part of the nose of a projectile and of substantially conic shape, said housing having an axially located chamber therein, an antenna element carried by said housing, and an oscillator unit within said chamber, said oscillator unit including an electron tube and a coil, said tube and coil being connected electrically to one another and to said antenna element for emitting radio frequency waves therefrom.

8. A fuze as defined in claim 7, wherein the end of the chamber at the larger end of the housing is open, and wherein the oscillator unit occupies only a portion of the length of the chamber, said fuze including also an amplifier unit between the oscillator unit and said open end of the chamber, said amplifier unit being electrically connected to said oscillator unit.

9. A fuze as defined in claim 7, wherein the electron tube of the oscillator unit is mounted axially within the chamber.

10. A fuze as dened in claim 7, wherein the electron tube of the oscillator unit is mounted axially within the chamber, and other circuit components of the oscillator unit including resistors and capacitors electrically connected with one another and with said coil and said electron tube, are mounted around it, also within the chamber.

1l. A fuze as defined in claim 7, wherein the chamber has a sleeve of insulating material mounted axially therein, the coil forming part of the oscillator unit being carried on the forward end of said sleeve, and the electron tube of the oscillator unit being mounted within the sleeve.

12. A radio proximity fuze comprising a substantially conical member made of insulating material, an antenna cap carried by said member near its vertex, said member having several substantially axial chambers therein of different bores, that of smaller diameter being nearest the vertex of the cone, an oscillator unit, a form made of insulating material and extending into several chambers, and carrying a coil, said coil constituting part of the oscillator unit, and being contained within a chamber relatively near the vertex, an electron tube also constituting part of said oscillator unit and housed within a portion of said form, and other elements of the oscillator unit including resistors and capacitors electrically connected to the coil and electron tube, said elements being mounted around said tube and housed in a larger one of the said chambers.

13. A radio proximity fuze, comprising, in combination with a projectile having a hollow nose, a source of oscillations including an electron tube, a coil, and a condenser electrically connected with one another so as to produce radio frequency oscillations, an insulating sleeve carrying said coil and disposed concentrically about said electron tube, and an amplifier unit electrically connected with the oscillator components, said oscillator components and amplier unit being wholly within said projectile nose.

14. In a radio proximity fuze, the combination with a projectile having a hollow substantially conical nose, a radio frequency oscillator unit including a thermionic tube, a coil, and a condenser, said tube being substantially axially disposed in said nose and electrically con nected to said coil and said condenser so as to produce radio frequency oscillations, and an ampliier unit electrically connected with the oscillator unit, said oscillator unit and amplifier unit being wholly within the projectile nose.

15. In a radio proximity fuze, an insulating nose unit having a substantially axially disposed chamber, and an oscillator unit of symmetrical assembly disposed in said chamber and including a substantially axially arranged electron tube, an insulating sleeve surrounding said electron tube, a coil wound upon said sleeve, and a capacitor, said last three electrical elements being electrically interconnected so as to produce radio frequency oscillations.

16. A radio proximity fuze comprising, electrically interconnected oscillator and amplifier portions, and a nose unit of insulating material having a substantially axially disposed chamber therein adapted to house said oscillator and amplifier portions, said oscillator portion being of symmetrical assembly including a substantially axially arranged electron tube connected so as to constitute a source of radio frequency oscillations, an insulating sleeve surrounding said tube, a coil, and a capacitor, said capacitor and said coil being electrically connected to one another and to other elements of said oscillator portion so as to produce radio frequency oscillations.

References Cited in the le of this patent UNITED STATES PATENTS 1,752,196 Patrie Mar. 25, 1930 1,755,023 Ruhlemann Apr. 15, 1930' 1,757,288 Bleecker May 6, 1930 2,255,245 Ferrel Sept. 9, 1941 f 2,341,351 Barkley Feb. 8, 1944 2,403,567 Wales July 9, 1946 2,404,553 Wales July 23, 1946 FOREIGN PATENTS 773,866 France Sept. 10, 1934 91,592 Sweden Feb. 24, 1938 546,488 Great Britain July 16, 1942 

